Year	Percent
1991-01-01	56.5474700327273
1992-01-01	55.9892374558853
1993-01-01	55.4766760011260
1994-01-01	55.5427746078373
1995-01-01	55.7857731904787
1996-01-01	55.8857167455343
1997-01-01	56.1877407890618
1998-01-01	56.2206674456228
1999-01-01	56.3707458901261
2000-01-01	56.6540845047731
2001-01-01	56.4939250370681
2002-01-01	56.0756021531652
2003-01-01	55.9636749889593
2004-01-01	56.0868248296328
2005-01-01	56.3879635385459
2006-01-01	56.8732572530338
2007-01-01	57.2364725301098
2008-01-01	57.1498631958160
2009-01-01	55.5698840715485
2010-01-01	55.2162268327665
2011-01-01	55.2044536079907
2012-01-01	55.2122684203244
2013-01-01	55.1908806557912
2014-01-01	55.5558053433191